A resistance-change type memory is known as one type of a semiconductor memory device. A magnetoresistive random access memory (MRAM) is also known as one type of the resistance-change type memory. The MRAM is a memory device using magnetoresistive elements having a magnetoresistive effect in memory cells that store information. As a writing method of the MRAM, there is a spin-transfer torque writing method. Since this spin-transfer torque writing method has the property that the spin-transfer torque current for magnetization switching becomes smaller as a magnetic substance decreases in its size, it is advantageous to high degree of integration, low power consumption and high performance.